This capacitive sensor that operates with a high frequency oscillator was found in Radio Electronics from the 90's. The circuit operates around 300 kHz.
This LED signaling circuit uses a programmable unijunction transistor (PUT) as a relaxation...
This decoder filter was found in a 1975 documentation. The integrated circuits can be 741. The...
We found this circuit in the January 1997 Electronics Now magazine. The triac determines the...